The present invention relates to polyarylene ether block copolymers according to the general formula A-K—X—K-A, where                —X— is a polyarylene ether segment with number-average molar mass of at least 5000 g/mol, and        A- is a segment of the general structure R2NH—(R1—NH—CO—Ar—CO—NH)n—R1—NH—, in which R1 is a linear or branched alkylene group having from 2 to 12 carbon atoms and Ar is an arylene group having from 6 to 18 carbon atoms, and R2 is selected from aryloyl, alkyloyl, and H, and in which the number average of n is from 1 to 3, and        there is a coupling group K of the structure —CO—Ar3—CO— linking each A to X, in which Ar3 is an aromatic group having from 6 to 18 carbon atoms.        
The present invention also relates to a process for the production of the polyarylene ether block copolymers of the invention, to polymer compositions comprising the polyarylene ether block copolymers of the invention, and also to the use thereof for the production of moldings, of films, of fibers, or of foams.
Polyarylene ethers are engineering thermoplastics, and their high heat resistance and high chemicals resistance leads to their use in very demanding applications. The literature has also disclosed that functionalized polyarylene ethers can be used as impact modifiers in thermoset matrices (R. S. Raghava, J. Polym. Sci., Part B: Polym. Phys., 25, (1987) 1017; J. L. Hedrick, I. Yilgor, M. Jurek, J. C. Hedrick, G. L. Wilkes, J. E. McGrath, Polymer, 32 (1991), 2020).
However, the stress-cracking resistance and solvent resistance of polyarylene ethers is unsatisfactory for many applications.
Husken et al., Polymer 45 (2004), 4837-4843 describe segmented block copolymers having uniform amide segments, composed of poly(tetramethylene oxide) segments and of tetramide segments.
WO 03/070806 describes segmented block copolymers which are composed of amide segments having at least 3 amide groups and of segments based on polymers with high glass transition temperature. The block copolymers have a multiblock structure which links the segments mentioned to one another in alternation. The segmented structure leads to rapid crystallization from the melt.
However, given comparable mechanical properties, the improvement that results from this type of segmented multiblock structure in terms of the solvent resistance and stress-cracking resistance of these high-glass-transition-temperature amorphous polymers is not adequate for all applications.